1. Field of the Invention
The invention relates to an assembly of a heat dissipating base and a lead frame for a light emitting diode packaging device and a method for making the same, more particularly to an assembly including a lead frame connected firmly to a heat dissipating base through at least one retaining member.
2. Description of the Related Art
Recent developments have resulted in improved luminance and power performance for light emitting diodes (LEDs). However, for high power LEDs, the working current can be as high as 330 mA to 1 A, which can generate enormous heat therein, which, in turn, results in an adverse effect on the service life of the LEDs.
FIG. 1 illustrates a conventional high power LED packaging device that includes a heat dissipating base 12 made of copper, an LED dice 1, a lead frame 13, a molding material 15 and a lens 14. The conventional LED packaging device 1 is prepared by adhesively attaching the LED dice 11 to the heat dissipating base 12 using a silver epoxy adhesive, placing the lead frame 13 in a mold (not shown), forming the molding material 15 through injection molding techniques so as to bond adhesively the lead frame 13 to the molding material 15, fitting the heat dissipating base 12 into a confining wall 151 of the molding material 15, connecting the LED dice 11 to the lead frame 13 through wire bonding techniques so as to permit connection to a circuit board (not shown), and covering a space above the LED dice 11 using the lens 14. However, since the heat dissipating base 12 is secured to the molding material 15 in a press fit manner, the heat dissipating base 12 tends to loosen therefrom, thereby resulting in poor heat dissipation and a reduction in the service life of the conventional LED packaging device 1.